Implantable medical devices, and in particular stimulus devices such as cardiac pacemakers, have for some time been software programmable. By software programmable, it is meant that the implanted device contains a form of microprocessor or microcomputer, and associated memory, the memory containing control software for controlling prescribed device operations. Such programmable software control has become necessary with the advent of more sophisticated and complex pacemaker devices, wherein real time operation can be achieved only with microprocessor-based control. For example, with the increased use of DDD pacing, and rate responsive pacing, as well as ongoing collection of events for diagnostic purposes, exclusive hardware control simply is no longer feasible. The demands for microprocessor control led to the development of pacemakers with platforms, or main building blocks, wherein the pacemaker can be modified by software downloaded into its memory. This technique enables producing different pacemaker types at the factory, or manufacturing site, by the simple expedient of loading the appropriate control program or programs into the pacemaker. The use of microprocessor-based pacemakers also enables a subsequent update of already implanted pacemakers, by downloading new control programs, or software, through the use of commercially available external programmer devices. Such capacity for downloading new control program software into an implanted pacemaker enables building a pacemaker device platform which is flexible enough to be software modified so as to adapt it for different applications and studies. For example, a pacemaker can be upgraded with new diagnostic tools and therapies to study the onset and prevention of atrial tacharrhythmias. A pacemaker implanted in a patient who was subsequently jeopardized by a different heart failure mode would have the capacity to have his implanted pacemaker modified to enable an appropriate new therapy and to carry out new diagnostic data accumulation. Of course, downloading of new software into an implanted pacemaker, i.e., using an external programmer to transmit a new control program for memory storage in the pacemaker, depends upon access to a programmer; the programmer must be capable of providing the desired software modification, and also be capable of more conventional programming of the pacemaker, e.g., setting stimulus pulse parameters, rate limits, etc.
It can be appreciated that with such technology, in the future there could be a large number of implanted pacemakers having the same hardware platform, but having been programmed differently either at the time of initial factory production or subsequently; and at the same time there might exist a large number of external programmers in use by physicians, each programmer equipped with a series of software updates depending upon the physician's access to the updates, interest in obtaining the updates, etc.
U.S. patent application Ser. No. 08/890,435 (Attorney Docket: V-0531), filed Jul. 9, 1997, titled "Pacemaker System With Enhanced Programmable Modification Capacity," now U.S. Pat. No. 5,843,138 discloses a cardiac pacemaker system having two-way telemetric capability between an implanted pacemaker and external programmer unit. This application is incorporated herein by reference in its entirety. In the system of the reference, there is provided an implantable device system, preferably a cardiac pacemaker system, having two-way telemetric capability between an implanted pacemaker and external programmer unit. The pacemaker suitably has memory for storing a control program, and also stores data representative of a predetermined group of pacemaker types, and data representative of the specific pacemaker type according to the control program stored in the pacemaker memory. Within each defined group, the different pacemaker types are ranked in a hierarchy, from lowest to highest. Each implantable pacemaker stores permissions data representative of the model types within its group to which it can be programmed. The external programmer can receive new program releases, i.e., updated control programs, and has memory for storing a plurality of control programs corresponding to pacemaker different types, the different pacemaker types falling in one or more different groups. The programmer is software controlled to interrogate the implanted pacemaker, determine its group, type and permissions, and allows modification, i.e., upgrading or downgrading of the control program as a function of the pacemaker data and the program types that it can support.
A critical problem that remains for such a flexible system is that of ensuring that the physician who wants to modify an implanted pacemaker is supplied with the pacemaker manual, and in particular an update of the manual in view of the new software release. A physician who has implanted a pacemaker in a patient presumably has a copy of the manual for that pacemaker. However, upon receiving a new software release, suitably provided by a CD-ROM disk, the physician should have available both the original manual and any new manual portion or section which relates to the new software release. Of course, the physician may have lost or misplaced his or her original copy of the manual; and in any event should have available the new manual portion describing the new control functions, as well as information regarding functions that might be removed by loading the new control software into the pacemaker and/or re-programming that would be required at the time of any such modification. In other words, there is a problem with respect to documentation, and a serious need to make complete manual information available at any time of modifying an implanted pacemaker with new control software. Even though new printed manual information might be supplied with the software, it might be some lengthy time later until the physician uses the new software, and the printed manual may not be available at that time. Further, it is expected that regulatory authorities, e.g., the FDA, will impose stringent rules concerning the availability of manual documentation at the time of software modification.
As an example of a commercially available programmer for use in a programmable pacemaker system, reference is made to the Medtronic/Vitatron 9790(c) programmer, which programmer is available for use in programming a family of pacemakers made by Vitatron Medical, B.V., the assignee of this invention. Such a programming system is capable of storing data corresponding to a manual applicable for such a family of pacemakers, and thus providing the capability of displaying the manual on-screen, or for printing the manual. However, there remains a need for a programmer for a pacing system which provides for up-to-date manual data which can be displayed and/or printed for any one of a family of pacemaker types, and, in particular, which provides for display and/or printing of manual changes at the time of programming an implanted pacemaker with new control software.